Re: Bug: Buffer cache is not scan resistant

On Mar 6, 2007, at 10:56 AM, Jeff Davis wrote:
>> We also don't need an exact count, either. Perhaps there's some way
>> we could keep a counter or something...
>
> Exact count of what? The pages already in cache?

Yes. The idea being if you see there's 10k pages in cache, you can  
likely start 9k pages behind the current scan point and still pick  
everything up.

But this is nowhere near as useful as the bitmap idea, so I'd only  
look at it if it's impossible to make the bitmaps work. And like  
others have said, that should wait until there's at least a first- 
generation patch that's going to make it into 8.3.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)